docstr: Sample LDA or SLDA topics for documents.
          
docstr_tok: ["Sample","LDA","or","SLDA","topics","for","documents","."]
code: def sample_doc(self, doc):
      """Sample LDA or SLDA topics for documents."""
      raise NotImplementedError
  
imports: import os
  import numpy
  from tqdm import tqdm
  from paddlehub.common.logger import logger
  from lda_novel.document import LDADoc, SLDADoc, Token, Sentence
  from lda_novel.vose_alias import VoseAlias
  from lda_novel.util import rand, rand_k
label_desc: Use image node_id 2 for calling the Sampler obj's underlying member method code with example usage: obj.sample_doc(doc) without return types